1. Field of the Invention
The present invention relates to a Ni-based superalloy having excellent oxidation resistance at high temperatures, and a gas turbine part made of the Ni-based superalloy. The Ni-based superalloy of the present invention is suitable for use in rotor blades and stator vanes of gas turbines.
2. Description of the Related Art
The combustion gas temperature in gas turbines tends to increase year by year for the purpose of increasing thermal efficiency. Correspondingly, gas turbine parts have been required to have more superior strength, hot corrosion resistance, and oxidation resistance at high temperatures.
Hitherto, Ni-based superalloys hardened with γ′-precipitation have been used in rotor blades and stator vanes of gas turbines. Also, improvements of material properties of alloys have been made by employing various chemical compositions, a variety of content ranges, and/or various methods for producing castings (see, for example, JP,A 6-57359 (claims), JP,A 6-184685 (claims), and Japanese Patent No. 2905473 (claims)).